In general, mobile communication systems have primarily been developed to provide voice communication services while guaranteeing user mobility. Mobile communication systems have gradually extended their scope of communication services to include high-speed data communication services as well as voice communication services. However, due to a lack of resources and a demand for higher-speed communication services by users in currently available mobile communication systems, an enhanced mobile communication system is needed.
To meet such requirements, a long term evolution (LTE) system, which is one of next-generation mobile communication systems under development, is being standardized in the 3rd generation partnership project (3GPP). LTE is technology for implementing high-speed packet based communication at a transmission rate of up to about 100 Mbps. Several schemes are being discussed to implement high-speed packet based communication. The schemes include, for example, a scheme for reducing the number of nodes on a communication path by simplifying the structure of a network and a scheme for maximally approximating radio protocols to radio channels.
A wireless communication system may include a plurality of base stations capable of supporting communication for a plurality of user equipments (UEs) (or terminals). A terminal may communicate with a base station on downlink and uplink. Downlink (or forward link) means a communication link from the base station to the terminal and uplink (or backward link) means a communication link from the terminal to the base station.
The base station may transmit data and control information to the terminal on downlink and/or receive data and control information from the terminal on uplink. Here, during the transmission of data and control information from the base station to the terminal on downlink, interference may occur due to transmission from neighboring base stations to other terminals. Interference may also occur on uplink during transmission from the terminal to the base station due to transmission from other terminals communicating with neighboring base stations. Such interference on downlink and uplink may deteriorate communication performance.
In the LTE system, inter-cell interference coordination (ICIC) is technology for enabling a base station to control interference by informing a neighboring cell of information about a maximum transmission power of a frequency resource used between cells. In more detail, the base station informs the neighboring cell of information about a resource block (RB) resource on which transmission is performed with a high power and information about an RB resource on which interference is sensed at a prescribed level or more among RB resources used in a cell thereof. Upon receiving the related information, the neighboring cell may adjust a transmission power and a scheduling method of an RB resource used thereby based on the received information.
In a heterogeneous environment of an LTE-advanced (LTE-A) system, a pico cell having a relatively low power is present in a macro cell having a relatively high transmission power. In this environment, however, an existing ICIC cannot show maximum performance due to severe interference between base stations. Accordingly, an ICIC technology in the time domain rather than in the frequency domain is needed and enhanced-ICIC (eICIC) based on the ICIC technology needs to be studied.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.